What causes an OCF fault on the ATS48 soft starter?


11 July 2023

OCF fault on ATS48

Product Line:
Altistart ATS48


Excessive motor current.

Troubleshooting steps 1.        
1) Check programming of the Soft start.   SEt menu   IN – must be set to the Motor FLA   ILT – Current limit: May need to increase to allow more current when starting.  Set too high can cause instant OCF faults on a run command   Acc – Acceleration: May need to increase   Tq0 – Initial starting torque( may not be visible depending on other settings); too high can cause OCF faults on run commandb.       DrC MenubSt – Voltage boost level; set too high may cause OCF on run commandCLP – Torque control; Some applications will respond better with this set to OFF (oscillations or surging during start).      
2) Check wiring from soft start to motor
3) Check for blockage of the motor( ensure the motor turns freely, if it is possible to check)
4) Check for correct rotation of motor
5) Check that the motor and the soft start are sized correctly
6) With motor connected, attempt to run motor and check the current draw on each phase of the output on the soft start.
7) If possible run motor across line and check current draw on each of the three phases (should be less than the full load amps of the motor and should be balanced on the three phases).If the motor does not run from line power or the current is high when running on line power, the problem is with the motor or the connected load.